Suspension device and system for a washing machine

ABSTRACT

A washing machine suspension device having a suspension shaft, a base member fixedly connected to the lower end of the suspension shaft, an elastic member located on the base member, and a support member having a central bore surrounding the suspension shaft, and a backing surface located above the base member. The support member has at least two compression members. Each compression member has a ramp that contacts the elastic member. The ramps are oriented such that a load is applied to the backing surface generates a reaction force between the support member and the elastic member to compress the compression member against the suspension shaft.

TECHNICAL FIELD

The present invention is related to dampers and suspension systems for washing machines.

DESCRIPTION OF THE STATE OF THE ART

The use of a suspension in tanks of washing machines is widely known in the industry. Using these devices is required for reducing vibrations in the machine during laundry and primarily during the centrifugation process, wherein the tank is rotated at elevated speed.

Document BRPI0603245A discloses a suspension assembly for washing machines that is widely known and used in the state of the art. In the described configuration, the suspension assembly is applied to a washing machine of the type comprising four shafts, having a superior end coupled to the structural cabinet of the washing machine and a lower end coupled to a tank in order to maintain it suspended inside the cabinet. The suspension is located at the lower end of the shaft such that the tank is supported on the top portion of the external capsule.

The suspension is comprised of the external capsule that contains within it a spring and a high density foam, wherein the foam is in contact with the inner wall of the capsule, such that relative movement of the foam with respect to the capsule generates friction. This, the spring is responsible for absorbing vibrations from the tank and the friction between the foam and the capsule is responsible for dissipating energy and as a consequence dampening the tank motion.

However, the used foam requires great dimensional precision, which makes it difficult for one to control the manufacturing process thereof in order to ensure power dissipation that is consistent with the requirements of the washing machine to which it is applied.

Also, another drawback of this solution is that, even though the suspension is in good operating conditions, the foam damping factor is constant for certain load ranges within the tank. Thus, when the tank contains a high load of clothes damping can be lower than the desired. Similarly, when the tank contains a low load of clothes damping can be higher than the desired.

OBJECT OF THE PRESENT INVENTION

The object of the present invention is to solve the aforementioned technical problem. Therefore, the objective of the present invention is to provide a washing machine suspension having a continuously variable damping factor that varies according to the load of clothes inside the tank.

Another objective of the present invention is to provide a washing machine suspension that provides greater process simplicity and production control, which should ensure greater functional stability of the damping mechanism.

SUMMARY OF THE INVENTION

In order to solve the aforementioned problem, the present invention provides a suspension device for a washing machine comprising: a suspension shaft; a base member fixedly connected to the lower end of the support shaft; a support member comprising: a central bore radially adjusted to the suspension shaft and capable of moving along it; a backing surface, wherein the support member is positioned above the base member; and an elastic member comprising a first end supported on the base member and a second end supporting the support member so as to maintain the same in suspension, wherein the support member further comprises at least two compression means radially adjusted with respect to the suspension shaft, projected towards the base member, each compression means comprising at least one ramp feature contacting the elastic member, such that when a load is applied to the backing surface, part of the reaction force of the elastic member onto the ramp features is transformed into a radial force, such that each compression means compresses the suspension shaft.

Furthermore, the present invention provides a suspension system for a washing machine comprising at least one suspension shaft, wherein each shaft comprises a lower end, and an upper end, wherein the upper end is coupled to a structural cabinet of the washing machine, wherein the system comprises at least one suspension device, wherein the lower end of the at least one suspension shaft is fixedly connected to the base member of the at least one suspension device, and wherein the support member supports the weight of the tank of the washing machine.

DESCRIPTION OF THE FIGURES

The above and further advantages as well as the components of the device of the present invention will be better understood by the skilled person by referring to the following description, taken in conjunction with the accompanying drawings, in which:

FIG. 1 illustrates a washing machine with a configuration of the suspension system of the present invention;

FIG. 2 illustrates a view of the isolated tank with the suspension system of FIG. 1;

FIG. 3 illustrates an optional configuration of a suspension device of the system of the present invention;

FIG. 3a illustrates a lower isolated viewed of the support member of FIG. 3;

FIG. 4 illustrates a view of an optional configuration of the support member of the present invention, wherein the spring is hidden;

FIG. 4a illustrates an isolated front perspective view of the support member 3 of FIG. 4; and

FIG. 4b illustrates an isolated rear perspective view of the support member 3 of FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION

The following description will be based on a preferred embodiment of the invention. As will be evident to the skilled person, however, the invention is not restricted to this particular embodiment.

FIG. 1 illustrates an optional configuration of the present invention, wherein the suspension system for the washing machine comprises four 10 supporting shafts (wherein only one shaft is illustrated), whose upper ends 12 are coupled to the structural cabinet 8 of the washing machine. The lower ends of the shafts 10, in turn, are connected to suspension devices 11.

As can be noted, the tank 7 of the washing machine is maintained in suspension by the shaft/suspension device assemblies 10/11. More specifically, the weight of the tank 7 is supported by the suspension devices connected to the lower ends of the shafts 10. Therefore, vibrations of the tank 7 caused by the process of washing or centrifuging clothes, for example, are minimized by the suspension devices 11, thereby reducing noise emission from the washing machine during these procedures.

FIG. 2 illustrates the configuration of the suspension system presented in FIG. 1 wherein the structural cabinet 8 of the washing machine is missing. This, it can be more clearly observed that the tank 7 comprises side support features 71 that are supported onto the suspension devices 11.

FIG. 3 illustrates an isolated view of a suspension device 11 of the system of the present invention comprising: a suspension shaft 10; a base member 2 fixedly connected to a lower end of the suspension shaft 10; a support member 3 positioned above the base member 2; and an elastic member 4.

In the illustrated configuration, the support member 3 comprises a central bore, which is radially adjusted to the suspension shaft 10 being movable along it. Furthermore, the support member 3 comprises a backing surface 31 on which the tank 7 of the washing machine is supported. Optionally, the tank 7 of the washing machine can comprise an auxiliary member 71 that is supported onto the backing surface.

The elastic member 4 optionally chosen in the disclosed configuration is a helical spring 4, wherein the first end of the spring 4 is supported onto the base member 2 and a second end of the spring supports the support member 3 so as to maintain it in suspension.

Further, the support member 3 comprises at least two compression means 32 radially adjusted with respect to the suspension shaft 10 and projected towards the base member 2. Each compression means 32 further comprises at least one ramp feature 321 in contact with the elastic member 4.

When a load is applied to the backing surface 31, the elastic member 4 is compressed by the ramp feature 321 of the ramp compression means 32 exerting a reaction force against the compression members 32. Thus, part of the reaction force of the elastic member 4 on the ramp members 321 is transformed in a radial force such that each compression means 32 compresses the suspension shaft 10, thereby increasing the frictional force between at least one compression means 32 and the suspension shaft 10.

Thus, in cases of vibration of the tank 7 of the washing machine, the elastic member 4 is responsible for absorbing the motion from the tank 7 and the at least two compression means 32 are responsible for damping the motion by dissipating energy by friction between the at least two compression means 32 and the suspension shaft 10.

Optionally, the compression means 32 is configured to be adjusted at least partially internally to the elastic member 4. Preferably, the adjustment is tightened such that the support member 3 is surrounded by the elastic member 4 restricting the relative movement between the members.

FIG. 3a illustrates an isolated lower view of an optional configuration of the support member 3 wherein the same comprises three compression means 32. In said optional configuration, the ramp members 321 of each of the compression means 32 comprises three angled fins 321 such that the elastic member 4 is in contact with these fins 321. Optionally, in each compression element 32, a fin 321 is located at each side thereof and a fin 321 is located at the center. Thus, the compression forces are radially and evenly distributed.

Optionally, the compression means 32 exhibit internally a semicylindrical shape for a better adjustment to the suspension shaft 10.

Optionally, as can be seen in FIG. 3, the edge 311 of the backing surface 31 of the support member 3 has a curved shape, such that the forces resulting from the weight of the tank applied to the surface 31 are also radially redirected, thus contributing for increasing the compressive force of the compression means 32.

With continued reference to FIG. 3a , the support member 3 optionally comprises a lubrication device 5 positioned above the backing surface 31. Said device may comprise any lubrication means for a shaft known in the state of the art. Lubrication is important for increasing the shelf life of the suspension device 11 of the present invention and to ensure that friction between the support shaft 10 and the compression means 32 is not excessively high.

FIG. 4 illustrates an isolated view with a hidden elastic member of an optional configuration of the present invention, wherein the support member 3 comprises two compression means 32, each comprising three angled fins 321.

FIGS. 4a and 4b illustrate, respectively, front and rear perspective views of the support member 3 of FIG. 4, wherein the same comprises a longitudinal tear 33 from the lower end to a point above the backing surface 31. In said configuration, the backing surface 31 is also divided in two by the tear 33. Therefore, the compression forces of the compression means 32 are increased since it is easier to bend the support member 3 towards the longitudinal axis of the suspension shaft 10.

Therefore, the present invention provides a suspension device 11 which, when the tank 7 contains a high load of clothes, and as a consequence, high weight, the compression means 32 of the support member 3 compress the suspension shaft 10 with greater strength, improving the damping effect of the suspension system.

Thus, the suspension system of the present invention automatically causes the damping factor for vibrations with full (heavier) tank 7 to be greater. While the damping factor for vibrations with empty (lighter) tank 7 is lower.

Accordingly, dampening of the system varies automatically with the amount of clothes inside the tank 7.

As will be evident to the skilled person, even though particular embodiments of the invention are presented, the same is not restricted to these particular embodiments. 

1. A suspension device for a washing machine, the suspension device comprising: a suspension shaft; a base member fixedly connected to bottom end of the suspension shaft; an elastic member having a first end supported on the base member and a second end distal from the first end; and a support member comprising: a central bore surrounding the suspension shaft above the base member, a backing surface, and at least two compression members located between the backing surface and the base member, each compression member comprising at least one ramp extending radially from the central bore to contact the elastic member at the second end of the elastic member, each ramp being oriented with a radial inward end relatively close to the base member and a radial outward end relatively far from the base member, such that a load applied to the backing surface generates a reaction force between the elastic member and the ramp to compress the compression member into the suspension shaft.
 2. The suspension device of claim 1, further comprising a lubrication device.
 3. The suspension device of claim 1, wherein the at least one ramp of each compression member comprises three sloped fins, wherein two of the three sloped fins are positioned at a respective side end of each compression member, and one of the three sloped fins is positioned in the center of the compression member.
 4. The suspension device of claim 1, wherein an edge of the backing surface is curved.
 5. The suspension device of claim 1, wherein the compression members are configured to adjust at least partially internally to the elastic member.
 6. The suspension device of claim 1, wherein the at least two compression members comprises two compression members.
 7. The suspension device of claim 6, wherein the support member comprises a longitudinal gap extending from an end of the support member closest to the base member to a point located above the backing surface.
 8. The suspension device of claim 1, wherein the at least two compression members comprises three compression members.
 9. A washing machine comprising: a structural cabinet; a tank; at least one suspension shaft having a lower end and an upper end, the upper end being coupled to the structural cabinet and the lower end being coupled to the tank by a suspension device comprising: a suspension shaft; a base member fixedly connected to bottom end of the support shaft; an elastic member having a first end supported on the base member and a second end distal from the first end; and a support member comprising: a central bore surrounding the suspension shaft above the base member, a backing surface, and at least two compression members located between the backing surface and the base member, each compression member comprising at least one ramp extending radially from the central bore to contact the elastic member at the second end of the elastic member, each ramp being oriented with a radial inward end relatively close to the base member and a radial outward end relatively far from the base member, such that a load applied to the backing surface generates a reaction force between the elastic member and the ramp to compress the compression member into the suspension shaft.
 10. The washing machine of claim 9, wherein the at least one suspension shaft comprises four suspension shafts, each suspension shaft being coupled to the tank by a respective suspension device. 